HDPE Wood-Plastic Composite Material Model Subject to Damage.

摘要

The information presented in this thesis is part of an ongoing research project being performed at Washington State University to develop wood-plastic composite materials for waterfront structures. Material development has been finished and relevant information can be found in reference papers. Current research efforts are focused on the development of material modeling using finite element software. A two-dimensional constitutive model capable of anisotropic nonlinearity was developed to describe the hyperbolic-tangent behavior of high-density polyethylene (HDPE) composites. The main objective of this thesis is focused on the application of an approach for the spectral decomposition of the elasticity tensor to include the effect of anisotropic behavior and the use of damage concepts to model nonlinearity and failure. A homogenized continuum based on the effective stress concept was adopted for the theory of anisotropic damage and elasticity. Damage variables were introduced to describe both the evolution of the tangent stiffness and the subsequent degradation and failure of the material.